Without the bypass hose from the thermostat housing to the water pump, water will not circulate through the block when the thermostat is closed. This will cause uneven heating of the engine. The water around the cylinders will get very hot, while the water near the thermostat will heat up slowly. Are you sure you have the right part number outlet for a 302? All the 302 outlets (3) in my FMS book have a bypass hose fitting.